1. Field of the Invention
The present invention is related to linear actuators for carrying read/write heads into engagement with a recording medium, and, more particularly, to a cover for the same.
2. Description of the Prior Art
Disk drives for storing electronic information are found in a wide variety of computer systems, including workstations, personal computers, and laptop and notebook computers. Such disk drives can be stand-alone units that are connected to a computer system by cable, or they can be internal units that occupy a slot, or bay, in the computer system. Laptop and notebook computers have relatively small bays in which to mount internal disk drives and other peripheral devices, as compared to the much larger bays available in most workstation and personal computer housings. The relatively small size of peripheral bays found in laptop and notebook computers, can place significant constraints on the designer of internal disk drives for use in such computers. Techniques that address and overcome the problems associated with these size constraints are therefore important.
Disk drives of the type that accept removable disk cartridges have become increasingly popular. FIG. 1 shows one disk drive product, known as the ZIP.TM. drive, that has been very successful. This disk drive is designed and manufactured by Iomega Corporation, the assignee of the present invention. ZIP.TM. drives accept removable disk cartridges that contain a flexible magnetic storage medium upon which information can be written and read. The disk-shaped storage medium is mounted on a hub that rotates freely within the cartridge. A spindle motor within the ZIP.TM. drive engages the cartridge hub when the cartridge is inserted into the drive, in order to rotate the storage medium at relatively high speeds. A shutter on the front edge of the cartridge is moved to the side during insertion into the drive, thereby exposing an opening through which the read/write heads of the drive move to access the recording surfaces of the rotating storage medium. The shutter covers the head access opening when the cartridge is outside of the drive, to prevent dust and other contaminants from entering the cartridge and settling on the recording surfaces of the storage medium.
The ZIP.TM. drive is presently available for workstations and personal computers in both stand-alone and internal configurations. In order to provide a version of the ZIP.TM. drive for use in laptop and notebook computers, the size constraints of the peripheral bays of such computers must be considered. In particular, for an internal drive to fit in the majority of laptop and notebook peripheral bays, the drive must be no longer than 135 mm. The height of the drive must be in the range of 12 to 15 mm. These dimensions place many constraints on the design of such a drive, and give rise to numerous design problems.
FIGS. 1 shows a prior art disk drive and cover 42 attached to the chassis. Conventional covers are made of typically made of a plastic or metal material. One drawback with employing a cover made of a plastic material with a disk drive is that the disk drive is relatively weak. It would, therefore, be desirable to provide a cover for a disk drive with improved strength.
Prior art disk drives typically have separate spring members welded or otherwise attached to the inner surface of the cover. These spring members are provided for biasing or pressing an inserted cartridge into an operating position. One drawback with having a separate spring member is that an additional component must be accounted for and separately attached to the cover. Another drawback is that the spring must be attached within certain tolerances which may be difficult to obtain. It would therefore be desirable to provide a means for positioning a cartridge without these drawbacks.
In the past, covers were attached to the chassis with adhesives or snap fits. One of the drawbacks with employing adhesives and snap fits to attach the cover to the chassis was that the cover was likely to slip under load conditions and, thereby, damage or misalign the internal components of the disk drive. To overcome this problem, fastening members such as screws were employed to perform the same function. The application of fastening members, however, created other problems. One of these problems was the fastening members could not maintain the desired rigidity of the cover because of the clearance required for the screw and therefore allow for cover and chassis slippage. It would therefore be desirable to provide a cover for a disk drive that maintains its rigidity after the cover is fastened to the disk drive.